A combined cycle plant uses both a gas turbine and a steam turbine to produce electricity. Electricity is generated first in the gas turbine cycle using natural gas fuel and then the steam turbine cycle.

Cycle 1: The Gas Turbine

In the gas turbine cycle, air is compressed then heated through the combustion of natural gas. The expansion of gases turns the turbine, which drives a generator, producing electricity.

Cycle 2: The Steam Turbine

Heat created in the first cycle (that would otherwise be wasted) is recovered to produce steam. This steam is provided to a steam turbine. Similar to the gas turbine cycle, the expansion of steam turns a steam turbine which drives a generator, producing electricity.

Adding the steam cycle to the gas turbine cycle increases the amount of electricity generated from a given amount of natural gas. Subsequently, there is greater fuel efficiency and fewer emissions produced per unit of electricity generated than would be produced by the gas turbine on its own.

About Napanee Generating Station

The proposed Napanee Generating Station is a 900-megawatt (MW), combined cycle, natural gas-fuelled electricity generating station located in the Town of Greater Napanee, County of Lennox and Addington, in Ontario.

The Napanee Generating Station will be designed as a flexible system resource able to be started and stopped daily and to vary its output to bridge the gap between Ontario’s electricity demand and the other available generating resources.